Ultra high frequency magnetron of the resonator type



y 1947. E. D. M ARTHUR ,7

ULTRA HIGH FREQUENCY MAGNETRON OF THE RESONATOR TYPE Filed March 20, 1943 n as a3 go A I 28 -1- 4/ 48 3/ 36 /J 35 l9 l4 ,2 g e so 32 17 I WA 'ez eamg Inventor: Elmer D. Mc Arthur ga /Attorney Patented July 8, 1947 ULTRA HIGH FREQUENCY MAGNETRON OF THE RESONATOR TYPE Elmer D. McArthur, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application March 20, 1943, Serial No. 479,925

11 Claims.

My invention relates to ultra high frequency conversion apparatus and more particularly to ultra high frequency magnetrons of the space resonant type.

It is an object of my invention to provide new and improved ultra high frequency conversion apparatus.

It is anotherobject of my invention to provide a new and improved ultra high frequency electric discharge devic of the magnetron type.

It is a further object of my invention to provide a new and improved ultra high frequency magnetron wherein a plurality of superimposed modulating effects act upon the space charge to derive from the magnetron electrical energy at a frequency corresponding to a resultant of the various excitations employed.

It is still another object of my invention to provide a new and improved ultra high frequency magnetron of a construction and arrangement which facilitate frequency conversion of ultra high frequency energy without entailing the use of separate electronic circuits or elements for accomplishing the results.

It is a still further object of my invention to provide new and improved methods of operating an ultra high frequency magnetron.

Briefly stated, in the illustrated embodiment of my invention, I provide a new and improved ultra high frequency electric discharge device of the magnetron type whereby ultra high frequency energy is readily converted. The electric discharge device comprises a metallic or conductive anode structure defining a plurality of space resonant regions or cavities, preferably having different natural frequencies, to produce therebetween electrode sections which serve as anode sections and which cooperate with a centrally positioned cathode. Upon the establishment of an electric field between the cathode and the anode structure and by the use of a magnetic field of proper intensity perpendicular to the electric field, there is imparted to the space charge a rotational motion. The space resonant cavities are excited at different frequencies, thereby mod-1 ulating the motion of the electrons within the space charge in accordance with a resultant of the excitation frequencies. For example, if two of the space resonant regions are energized at different frequencies, there will be imparted to 'the electrons of the space charge motions producing frequencies corresponding to the sum and the difference of the excitation frequencies, thereby producing across the anode'structure and the cathode of the discharge device potential differences corresponding to the resultant frequencies. Suitably tuned external utilization means, such as an intermediate frequency circuit or amplifier, may be connected to the output terminals of the discharge device for utilization of the resultant frequencies. v

For a better understanding of my invention, reference may be had to th following descrip tion taken in connection with the accompanying drawingand its scope will be pointed out in the appended claims. Fig. 1 of the drawing shows my invention as applied to a magnetron in which the magnetic field is produced by a pair of permanently magnetized pole pieces located within the enclosing envelop for the electrodes, aand Fig. 2 is a plan view of the anode structure which defines the various space resonant cavities.

Referring now to Fig. 1 of the drawing, I have there illustrated my invention as applied to a magnetron of the type generally W disclosed and claimed in my copending patent application Serial No. 447,903,1iled June 22, 1942, and which is assigned to the assignee of the present application. I I

The electrodes of the discharge device there illustrated may be enclosed within an elongated cylindrical container, the lateral wall structure of which is provided by a, single metal tube 1 which consists of a ferromagnetic material. The ends of the container are closed by flanged members 2 and 3 which are welded or otherwise hermetically sealed to the inner surface of tube I.

Within the container and approximately at its central region, I provide an anode structure 4 shown in plan view in Fig. 2. The annular anode structure 4 is preferably of disk formation of appreciable longitudinal length and may be constructed of a suitable metal such as copper. Within the anode structure 4 there is provided an enllarged central openingv 5 in which a cathode structure described hereinafter is positioned.

As a means for the utilization of ultrahigh frequency electrical energy and in order to mod-' ulate the spac charge which is establishedbetween a centrally located cathode and the electrode or anode sections 6 and 1, I provide within the anode structure 4 a plurality of annularly or circumferentially positioned space resonant regions. These regions may take the form as illustrated in Fig. 2 in which one'cavity comprises a cylindrical opening 8 in communication with the central opening 5 through aradial slot 9, and the other of which comprises a cylindrical opening ID in communication with the central opening through a radially extending slot l I.

resultant electric field giving rise to a modulated current'containing the sum and the difference of these twofrequencies- Consequently; there will appear between the anode structure 4' and cath- Ode sleeve 30, components of voltage corresponding to the sum and the difference frequencies. The resultant voltages appearing between the anode structure an cathode 30'are utilized for the purpose of energizing. an external utilization circuit, such as circuit 41, which is energized through a circuit 48 tuned to a selected resultant or intermediate frequency.

While Ihave'shown and described my invention a applied to a particular form of magnetron, it will-be obvious to those skilled in the art that changes and modifications may b made without departing-from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention. I

What I claim as new and desire to secure by Letters Patent of the United States is: Y

1. An ultra high frequency electric discharge device of the magnetron type comprising a'cathode and an anode structure having a central opening through which said cathodeextends and having in communication therewith a plurality of space resonant cavities, mean for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes therebetween a rotating space charge, means for exciting one of said cavities at one frequency, and means for exciting another cavity at a different frequency thereby establishing across said cathode and said anode structure a voltage corresponding to a resultant of the above frequencies. 3

2. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and a disk-type anode structure having a central opening through which said cathode extends and having in communication therewith a plurality of space resonant cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structur and said cathode establishes therebetween a rotating space charge, means for exciting one of said cavities at one frequency, and means for excitin the other cavity at a different frequency thereby establishing across said anode structure and said cathode a voltage corresponding to a resultant of the above mentioned frequencies.

3. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and a disk-like anode structure having a central opening through which said cathode extends and having in communication therewith a, plurality of annularly positioned space resonant cavities, means for establishing a magnetic field extending longitudinally through said central open- 7 ing, means for establishing an electric field between said anode structure and said cathode and which in conjunction with said magnetic field establishes a rotating space charge, means for exciting one of said cavities at one frequency, and means for exciting another cavity at a different frequency thereby producing across said anode structure and said cathode a voltage corresponding to a resultant of the above mentioned frequencies.

4. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and an anode structure having a central opening through which said cathode extends and having in communication therewith a pair of space resonant cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes therebetween a rotating space charge, means for exiting" on of said'cavities at one frequency,

" means for exciting the other cavity at a different frequency, and means connected to said cathode and Said anode structure energized in accordance with a resultant of the first mentioned and second mentioned frequencies.

5. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and an anode structure having a central opening through which said cathode extends and having in communication therewith a pair of space resonant cavities having different predetermined natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes a rotating space'charge therebetween, means for exciting one of the cavities at its natural frequency, and means for exciting the other cavity at a different frequency thereby modulating said space charge in accordance with a resultant of said frequencies and producing across said anode structure and said cathode a high frequency voltage corresponding to said resultant frequency.

6. An ultra high frequency electric dis-charge device of the magnetron type comprising a cylindrical cathode and an annular anode structure having a central opening through which said cathode extends and having in communication there with a pair of space resonant cavities each comprising a cylindrical opening radially displaced from said central opening and in communication therewith through a radial slot, said cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes a rotating space charge therebetween, and means for exciting said cavities at different frequencies thereby modulating the space charge in accordance with a resultant of said frequencies and producing across said anode structure and said cathode a potential difference corresponding to said resultant.

'7. Frequency conversion electric discharge apparatus of the space resonant type comprising a plurality of enclosed electrodes including a cathode and an anode structure having a central opening through which said cathode extends and having in communication therewith a pair of space resonant cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes a rotating space charge therebetween, means for exciting said cavities at different frequencies to modulate the space charge in accordance with said frequencies, and means connected to said anode structure and said cathode for utilizing the potential difierence thereacross corresponding to either the sum or difference frequency.

8. Ultra high frequency conversion apparatus of the magnetron type comprising an electric discharge device including a plurality of enclosed electrodes including a cathode and an anode structure having a central opening through which said cathode extends and having in communication therewith a. pair of space resonant cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode and said cathode establishes a rotating space charge therebetween, means for exciting said cavities at different frequencies and for modulatin the space charge in accordance with said frequencies, and intermediate-frequency utilization means connected across said anode structure and said cathode.

9. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and an anode structure having a central opening through which said cathode extends and having in communication therewith a plurality of space resonant cavities having different natural frequencies, means for establishing a magnetic field which with an electric field applied across said anode structure and said cathode establishes therebetween a rotating space charge, externally accessible means coupled with one of said cavities for effecting excitation thereof at one frequency, and a second externally accessible means coupled with another of said cavities for effecting excitation thereof at a different frequency thereby producing across said anode structure and said cathode a high frequency potential difference corresponding to a resultant of the above mentioned frequencies.

10. An electric discharge device of the magnetron type comprising a cathode and an anode structure defining a plurality of space resonant cavities, means for applying a unidirectional potential across said anode structure and said cathode, means for controlling the space discharge between said anode structure and said cathode including means for exciting one of said cavities at one frequency, means for superimposing a modulating effect on said space charge including means for exciting another cavity at a different frequency and means for deriving electrical energy from said cathode and said anode structure at a frequency which is a resultant of the first mentioned and-second mentioned frequencies.

11. An ultra high frequency electric discharge device of the magnetron type comprising a cathode and an anode structure having a plurality of space resonant cavities, means for impressing an electric field between said anode structure and said cathode, means for producing a magnetic field in the region between said anode structure and said cathode which is substantially perpendicular to said electric field to produce a rotating space charge between said cathode and said anode structure, means for controlling the space charge including means for exciting one of said cavities at one frequency, and means for superimposing a modulating effect on said space charge by exciting another cavity at a different frequency thereby producing across said cathode and said anode structure a high frequency potential difference corresponding to a resultant of the first mentioned and second mentioned frequencies.

ELMER D. McARTI-IUR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Engel Feb. 18, 1936 

